In dealing with matters of national sensitivity, it is advisable for politicians to tread carefully or reap consequences that may mark them down in history in ways they would not wish. In the seven days since David Cameron called on Alex Salmond, Scotland's first minister and leader of the SNP, to hold a quick and clean referendum on home rule for Scotland, he appears to have fuelled rather than neutralised the desire for greater freedom on the part of a growing number of Scots. Where this ends may yet mean that David Cameron, "passionate" abut the 300-year-old Union, is nevertheless the prime minister on whose watch it begins to sunder.

Two years hence, 2014, promises to be an eventful year for Scotland. It hosts the Commonwealth Games, the Ryder Cup and celebrates the 700th anniversary of Bannockburn, the battle in the first war for Scottish independence in which Robert the Bruce won a significant victory against Edward II. Alex Salmond also intends that, in 2014, the Scots will have a referendum, "made, built and organised in Scotland", that gives the choice of full independence.

What the polls indicate is that a majority of Scots would prefer a second option, known as "devo max". So far, it is ruled out by the coalition and Labour. Devo max would give Scotland fiscal autonomy. Holyrood would set, raise and keep all taxes, remitting to London Scotland's shares of common costs on foreign affairs and defence. As David Steel, former leader of the Liberal party and knight of the Order of the Thistle has said, in support of greater fiscal independence, and the responsibility that comes with it: "No self-respecting parliament can exist permanently on a grant from another parliament."

Last week, Cameron attempted to seize the initiative by demanding a yes/no referendum within 18 months. Backed by Ed Miliband, he argued that the United Kingdom is "stronger together than it is apart". On Tuesday, Michael Moore, the coalition's Scottish secretary, said the referendum should be "legal, fair, decisive" but he also pointed out that the Scottish parliament could not legislate on matters only reserved for Westminster. In doing so, he reminded many Scots precisely why there is a shift in ever larger numbers in favour of renegotiating the relationship.

Since then, the insults have flowed to no great advantage. Salmond has accused Westminster of "bullying" and has ill-advisedly compared the SNP's bid for independence with Ireland's violent struggle against the British (in which many Scots supported the British writ). In turn, he has been called "a bandit" and accused of "showing his vanity", hardly a vice restricted to one Scottish politician. Lord Ashdown has also waded in reducing an issue of huge import to four countries, to a "High Noon" between Cameron and Salmond. Salmond has invited Nick Clegg and Cameron to talks; they say, address yourself to Michael Moore, another barbed reminder of Scotland's position in the UK. So where is the clarity for which Moore has called?

Scotland is a relatively small country of 5.2 million. Under the Barnett Formula, devised in the 1970s, public spending is accorded to Scotland, Wales and Northern Ireland according to population size rather than need. It has served Scotland well. According to research by the University of Stirling, England "loses" £4.5bn of public money to Scotland annually. In counterbalance, in 2011-12, Scotland's oil and gas revenue will amount to £11bn (halved since 1999), 0.7% of UK national income and eventually due to run out.

As Neal Ascherson writes opposite, Scotland is a deeply conservative country. Paradoxically, that means it has resisted the neo-liberal agenda in England, and hung on to the consensus that resists privatisation and holds faith with the power of the welfare state to stoke social mobility.

Adopting a "social democratic" agenda, since it came to power the SNP has invested in transport infrastructure and early years development. Council tax is frozen, the NHS budget is protected in "real terms", universities are free as is social care for older people. But there are rocks ahead. Greater fiscal independence will also require less popular accounting decisions. Scotland, for instance, has a higher proportion of older people. As Paul Johnson of the Institute for Fiscal Studies points out, should separation come: "Even if you have a happy year one, year 10 may look more difficult."

Independence, at this stage, appears unlikely but a route that begins with a "social union" and possibly moves on to devo max isn't far from the final destination of a clean break. We are, after all, living in an era of such journeys. Estonia seceded from the Soviet Union in the 1990s; Montenegro seceded from Serbia in 2006. The EU is overflowing with small states, drawing strength in healthier financial times from a federation. They uphold a basic principle in international law that a country has a right to self determination.

Now, a Westminster-based tartan posse including Alistair Darling and Charles Kennedy, is intent on persuading would-be separatists that the status quo is best. They will warn that Scottish independence demands a radical reconfiguration of the UK constitution. As Carwyn Jones, first minister for Wales has said, minus the Scottish MPs, parliament would consist of 550 MPs, 510 from England. Should that happen, he is calling for plans for a senate and fair representation of the three remaining countries in the then less united kingdom.

Such ramifications need to be aired. Intransigence on the part of Mr Cameron isn't helpful. To coerce the SNP into holding a referendum at a time it resists is to be avoided at all costs. So, the sooner a grown-up debate commences, home truths heard and the name-calling ceases, the better. What is also welcome is the opportunity this might offer to consider the possible continuing evolution of the United Kingdom. Could it become a loose federation in which, for instance, Scotland has "secure autonomy", independent in all but name and minus the shadow of assumed English superiority?

Scotland is about to participate in the greatest democratic exercise in its history. It is important that others in the United Kingdom are active participants and their voices are heard too. If that happens, we may yet forge a stronger set of institutions from which a modernised version of the UK can be built of which we are all proud to be called citizens.